WO2009119843A1 - Raw material introduction apparatus for molten iron making and method for introducing raw material for molten iron making - Google Patents

Raw material introduction apparatus for molten iron making and method for introducing raw material for molten iron making Download PDF

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Publication number
WO2009119843A1
WO2009119843A1 PCT/JP2009/056381 JP2009056381W WO2009119843A1 WO 2009119843 A1 WO2009119843 A1 WO 2009119843A1 JP 2009056381 W JP2009056381 W JP 2009056381W WO 2009119843 A1 WO2009119843 A1 WO 2009119843A1
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temperature
reduced iron
low
charging
melting furnace
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PCT/JP2009/056381
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French (fr)
Japanese (ja)
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雅孝 立石
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株式会社神戸製鋼所
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B19/00—Combinations of furnaces of kinds not covered by a single preceding main group
    • F27B19/04—Combinations of furnaces of kinds not covered by a single preceding main group arranged for associated working
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B13/00—Making spongy iron or liquid steel, by direct processes
    • C21B13/10—Making spongy iron or liquid steel, by direct processes in hearth-type furnaces
    • C21B13/105—Rotary hearth-type furnaces
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B13/00—Making spongy iron or liquid steel, by direct processes
    • C21B13/14—Multi-stage processes processes carried out in different vessels or furnaces
    • C21B13/143—Injection of partially reduced ore into a molten bath
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/56—Manufacture of steel by other methods
    • C21C5/567—Manufacture of steel by other methods operating in a continuous way
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B3/00—Hearth-type furnaces, e.g. of reverberatory type; Tank furnaces
    • F27B3/10—Details, accessories, or equipment peculiar to hearth-type furnaces
    • F27B3/18—Arrangements of devices for charging
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/14—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment
    • F27B9/16—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a circular or arcuate path
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/52—Manufacture of steel in electric furnaces
    • C21C5/527—Charging of the electric furnace
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/0025—Adding carbon material
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/20—Recycling

Definitions

  • the present invention uses two or more charging devices, a high temperature charging device and a low temperature (room temperature) charging device, and controls raw material charging from the low temperature charging device, thereby providing a rotary hearth furnace and a melting furnace.
  • This invention relates to a molten iron manufacturing raw material charging apparatus and a molten iron manufacturing raw material charging method capable of improving the matching, improving the productivity, and improving the plant operating rate.
  • the process of reducing iron ore with gas or solid carbon to produce solid reduced iron is generally called the direct reduced iron production process: the DR process (Direct reduction process), and the reduced iron obtained by this iron production process is DRI (Direct reduced iron).
  • a shaft furnace type and a rotary hearth furnace type represented by the Midrex method are known.
  • powdered iron ore and coal are mixed and granulated into pellets or briquettes, reduced in a donut-shaped rotary furnace, then melted in a melting furnace at a high temperature to form hot metal. To manufacture.
  • the reduction furnaces such as shaft furnaces and rotary hearth furnaces are basically operated continuously. On the other hand, since the melting furnace provided in the downstream needs to be maintained regularly, the operation cycle is different from the reducing furnace provided in the upstream.
  • the operating cycle of the melting furnace is shorter than the cycle of the reducing furnace, and the productivity of the reducing furnace and the melting furnace does not match at startup.
  • a high-temperature reduced iron storage tank is provided in order to achieve matching between a continuously operated reducing furnace and a relatively non-continuously operated melting furnace.
  • the high-temperature reduced iron discharged from the reduction furnace is temporarily stored in the high-temperature reduced iron storage tank, and reduced iron is supplied according to the needs of the melting furnace.
  • the present invention has been made in consideration of the problems in the conventional DR process as described above.
  • the present invention improves the matching between a rotary hearth furnace that is operated continuously and a melting furnace that is operated in batch, maintains productivity, and can increase the operating rate of the reduction furnace and melting furnace, and can input raw materials for molten iron production
  • An apparatus and a raw material charging method for producing molten iron are provided.
  • the raw material charging apparatus for producing molten iron includes a high-temperature charging system for supplying hot high-temperature reduced iron produced by a direct reduction steelmaking process to a melting furnace, and cooled low-temperature reduced iron and carbonaceous material in the melting furnace.
  • a raw material charging device for producing molten iron having a low temperature charging system to supply The high temperature charging system includes a high temperature storage container for storing reduced iron discharged hot, and a quantitative cutting device for supplying the high temperature reduced iron in the high temperature storage container to the melting furnace in a predetermined amount.
  • the charging system for low temperature includes a first hopper for storing the low-temperature reduced iron, a feeder for adjusting a cutting amount of the low-temperature reduced iron from the first hopper, a second hopper for storing carbonaceous material, and the second hopper. And a feeder that adjusts the amount of carbon material cut out from the hopper.
  • the molten iron production raw material charging device has a charging chute for charging low-temperature reduced iron and carbonaceous material cut out from the first hopper and the second hopper into the melting furnace, and generates the generated gas in the melting furnace. It is preferable that a blocking device for preventing intrusion is interposed in the charging chute.
  • the cutting ability of the low temperature charging system is preferably 0 to 30% of the cutting capacity of the high temperature charging system.
  • the raw material charging method for producing molten iron according to the present invention includes a high-temperature charging system for supplying hot high-temperature reduced iron produced by a direct reduction iron-making process to a melting furnace, and cooled low-temperature reduced iron and carbon material in the melting furnace.
  • a low-temperature charging system to supply The low-temperature reduced iron and the carbonaceous material are supplied from the low-temperature charging system to the melting furnace at a controlled charging speed, and after the low-temperature reduced iron is dissolved in the melting furnace, the raw material is charged for the low-temperature.
  • the gist is that the input system can be switched to the high temperature input system.
  • the low temperature reduced iron In the state where the high temperature reduced iron is supplied hot by the high temperature charging system, when a predetermined amount of the low temperature reduced iron is charged from the low temperature charging system and the molten metal temperature tends to decrease, the low temperature reduced iron is used.
  • the molten metal temperature tends to rise, the molten metal temperature can be kept constant by increasing the low-temperature reduced iron charging speed while keeping the high-temperature reduced iron charging speed constant. it can.
  • the raw material charging method for producing molten iron according to the present invention includes a high temperature charging system for supplying hot high-temperature reduced iron produced by a direct reduction iron-making process to a melting furnace, and melting the cooled low-temperature reduced iron and carbonaceous material as described above.
  • a low-temperature charging system for supplying to the furnace In a state where the high temperature reduced iron is supplied hot by the high temperature charging system, a predetermined amount of the low temperature reduced iron is charged from the low temperature charging system, and when the molten metal temperature tends to decrease, the low temperature reduced iron is charged.
  • the gist is to keep the melt temperature constant by lowering the speed and increasing the charging speed of the low-temperature reduced iron when the melt temperature tends to rise.
  • the present invention has the advantage that the matching between the reducing furnace operated continuously and the melting furnace operated discontinuously can be improved, and the operating rate of each furnace can be increased while maintaining a predetermined productivity.
  • FIG. 1 shows a configuration in a case where a raw material charging apparatus for producing molten iron according to the present invention (hereinafter referred to as a raw material charging apparatus) is directly applied to a reduction iron making facility.
  • a raw material charging apparatus for producing molten iron according to the present invention
  • a direct reduction iron making facility 1 has a rotary hearth type heating reduction furnace (hereinafter referred to as a rotary hearth furnace) 2, and the rotary hearth 2 a of the rotary hearth furnace 2 is counterclockwise ( It rotates in the direction of arrow A).
  • a rotary hearth furnace a rotary hearth type heating reduction furnace
  • the rotational speed of the rotary hearth furnace 2 varies depending on the size and operating conditions of the heating and reducing furnace, but usually makes one turn in about 6 to 16 minutes.
  • a plurality of heating burners 2c are provided on the wall surface of the furnace body 2b in the rotary hearth furnace 2, and heat is supplied to the hearth by combustion heat or radiant heat generated by these heating burners 2c.
  • the raw material mixture M charged on the rotary hearth 2a made of refractory material moves in the rotary hearth furnace 2 in the circumferential direction on the rotary hearth 2a, the combustion heat and radiant heat from the heating burner 2c. Heated by.
  • the iron oxide in the raw material mixture M is reduced and separated from the by-product molten slag and melted by receiving carburization with the remaining carbonaceous reducing agent. However, it aggregates in a granular form and becomes granular reduced iron N.
  • the granular reduced iron N discharged from the rotary downstream zone of the rotary hearth furnace 2 at a high temperature is accommodated in the high temperature DRI transfer container 3 and moved to the raw material charging device 4.
  • the raw material charging device 4 melts the cooled low-temperature reduced iron and carbonaceous material, and the high-temperature charged system 10 for supplying hot high-temperature reduced iron produced in the direct reduction steelmaking process to a melting furnace described later. And a low temperature charging system 11 to be supplied to the furnace.
  • High temperature charging system The high temperature DRI transport container 3 moved to the high temperature charging system 10 of the raw material charging device 4 is connected to the upper connection portion 5 a of the intermediate bin (high temperature storage container) 5.
  • the intermediate bin 5 includes an upper slide gate 5b and a lower slide gate 5c.
  • a water-cooled screw feeder (quantitative cutting device) 6 as a high-temperature charging device is provided below the intermediate bottle 5, and a feed bin 7 with a load cell is further provided below the water-cooled screw feeder 6. Is provided.
  • controllability is poor below the lower limit of the cutting ability and cannot be used.
  • the water-cooled screw feeder 6 of this embodiment is no exception, and the minimum controllable charging speed was about 1,000 kg / h (about 20% of the rating).
  • the cutting capacity (rated) of the vibration feeder in the low temperature charging system 11 is 1.5 t / h
  • a control range of at least 0 to 30% of the cutting capacity in the high temperature charging system 10 is set for low temperature. It is possible to cover with the input system 11.
  • the cutting ability of the vibration feeder is set to 30% so that the high temperature charging system 10 can be substituted even in the case described above.
  • the scale of the raw material charging device 4 is increased, which not only increases the plant cost but also complicates the control.
  • a plurality of vibration feeders having a cutting ability of 30% or less can be provided according to the matching status of the continuous process.
  • the feed bin 7 is provided with an upper slide gate 7 a and a lower slide gate 7 b, and the lower portion of the feed bin 7 is connected to the melting furnace 9 through the charging unit 8.
  • slide gates 7a and 7b are provided. Since the input system upstream of the feed bin 7 has low sealing performance, exhaust gas generated during the operation of the melting furnace flows into the upstream side of the feed bin 7 and comes into contact with the outside air, which may cause ignition. The upper and lower slide gates 7 a and 7 b of the feed bin 7 have an effect of preventing exhaust gas from flowing into the upstream side of the feed bin 7.
  • the slide gates 5b and 5c and the slide gates 7a and 7b are provided in order to prevent the gas generated from the melting furnace 9 from entering the high temperature charging system 10.
  • the charging unit 8 is provided with a low temperature charging system 11 in addition to the high temperature charging system 10.
  • the low temperature charging system 11 includes a low temperature DRI hopper (first hopper) 12, a vibration feeder (feeder) 13 as a low temperature charging device for cutting out the low temperature DRI from the low temperature DRI hopper 12, and a coal hopper (second hopper). Hopper) 14, a vibration feeder (feeder) 15 as a low temperature charging device for cutting out carbonaceous material from the coal hopper 14, and a conveyor 16 for conveying the raw material supplied from these hoppers forward
  • the hopper 16a provided at the front end portion of the conveyor 16 and the chute (feed chute) 17 communicating with the throwing portion 8 and a rotary valve (blocking device) 17a provided on the chute 17 are mainly configured. ing.
  • shut-off device is not limited to the rotary valve, and can be constituted by a double damper on-off valve or the like.
  • the rotary valve 17a prevents gas generated from the melting furnace 9 from entering the low temperature charging system 11.
  • the said vibration feeder as a continuous cutting device, it is not restricted to this, Feeders of other systems, such as a screw feeder and a table feeder, can also be used.
  • the melting furnace 9 is provided with an oxygen blowing lance 18 for blowing high-purity oxygen toward the slag layer on the molten metal surface of the melting furnace 9.
  • an oxygen blowing lance 18 for blowing high-purity oxygen toward the slag layer on the molten metal surface of the melting furnace 9.
  • FIG. 2 is a graph showing the control operation from the initial operation to the stationary phase of the melting furnace 9, and it is assumed that the rotary hearth furnace 2 is continuously operated.
  • the horizontal axis indicates the elapsed time (minutes) from the start of blowing.
  • the vertical axis on the left indicates the acid feed rate (Nm 3 / h) and the carbonaceous material / DRI feed rate (kg / h).
  • the right vertical axis indicates the molten metal temperature (° C.).
  • the acid feed rate O is constant, and the carbonaceous material feed rate C is constant after 10 minutes.
  • the raw material charging apparatus 4 of the present invention includes a low temperature charging system 11 separately from the high temperature charging system 10.
  • the amount of reduced iron N discharged from the rotary hearth furnace 2 can be supplied to the melting furnace 9 as it is by controlling the amount of the low temperature DRI and the carbonaceous material charged from the low temperature charging system 11.
  • the carbonaceous material is added to reduce slag containing FeO at a high concentration.
  • the low temperature DRI charging speed L and the carbonaceous material charging speed C are increased step by step from the start-up of the melting furnace 9.
  • an arrow B indicates the timing of switching from low temperature DRI input to high temperature DRI input.
  • FIG. 3 is a graph showing the charging operation for performing steady operation.
  • the high temperature DRI charging speed H is constant. Further, the carbon material charging speed C and the acid feeding speed O are also constant.
  • the low temperature DRI charging speed L is slightly decreased (in the graph, the falling portion L 3 ).
  • the raw material charging device of the present invention is interposed between the rotary hearth furnace and the melting furnace.
  • the raw material charging apparatus of the present invention is not limited to a rotary hearth furnace, and can be interposed between any furnace that performs a direct reduction iron making process and a melting furnace.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacture Of Iron (AREA)
  • Furnace Charging Or Discharging (AREA)
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Abstract

Provided is a direct reduction iron making equipment, in which matching between a continuously operated rotary hearth furnace and a batch operated melting furnace is improved and high productivity can be realized. A raw material introduction apparatus for molten iron making comprises an introduction system (10) for high temperature use that introduces a high-temperature reduced iron, produced by a direct reduction iron making process, in a hot state into a melting furnace (9), and an introduction system (11) for low temperature use that introduces a cooled low-temperature reduced iron and a carbon material into the melting furnace (9). The introduction system (10) for high temperature use comprises a storage container (5) for high temperature use that stores a reduced iron discharged in a hot state, and a constant quantity take-off device (6) that introduces a high-temperature reduced iron within the storage container (5) for high temperature use by predetermined amount into the melting furnace (9). The introduction system (11) for low temperature use comprises a first hopper (12) that stores a low-temperature reduced iron, a feeder (13) that regulates the amount of the low-temperature reduced iron taken off from the first hopper (12), a second hopper (14) that stores the carbon material, and a feeder (15) that regulates the amount of the carbon material taken off from the second hopper (14).

Description

溶鉄製造用原料投入装置および溶鉄製造用原料投入方法Raw material input device for manufacturing molten iron and raw material input method for manufacturing molten iron
　本発明は、高温用投入装置と低温（常温）用投入装置との二つ以上の投入装置を併用し、その低温用投入装置からの原料投入を制御することにより、回転炉床炉と溶解炉のマッチングを改善し、生産性を高め、また、プラント稼働率を向上させることができる溶鉄製造用原料投入装置および溶鉄製造用原料投入方法に関するものである。 The present invention uses two or more charging devices, a high temperature charging device and a low temperature (room temperature) charging device, and controls raw material charging from the low temperature charging device, thereby providing a rotary hearth furnace and a melting furnace. This invention relates to a molten iron manufacturing raw material charging apparatus and a molten iron manufacturing raw material charging method capable of improving the matching, improving the productivity, and improving the plant operating rate.
　鉄鉱石をガスまたは固体炭素で還元し、固体の還元鉄を製造するプロセスを、一般に直接還元鉄製鉄法：ＤＲプロセス（Direct reduction process）と呼び、この製鉄法によって得られる還元鉄をＤＲＩ（Direct reduced iron）と呼んでいる。 The process of reducing iron ore with gas or solid carbon to produce solid reduced iron is generally called the direct reduced iron production process: the DR process (Direct reduction process), and the reduced iron obtained by this iron production process is DRI (Direct reduced iron).
　ＤＲプロセスとしては、ミドレックス法に代表されるシャフト炉タイプや回転炉床炉タイプ等が知られている。 As the DR process, a shaft furnace type and a rotary hearth furnace type represented by the Midrex method are known.
　回転炉床炉タイプによるＤＲプロセスでは、粉状の鉄鉱石と石炭を混合・造粒してペレットまたはブリケット状にし、ドーナッツ状の回転炉で還元した後、高温のまま溶解炉で溶かして溶銑を製造する。 In the DR process using the rotary hearth furnace type, powdered iron ore and coal are mixed and granulated into pellets or briquettes, reduced in a donut-shaped rotary furnace, then melted in a melting furnace at a high temperature to form hot metal. To manufacture.
　この種のＤＲプロセスによれば、従来のような焼結炉やコークス炉が必要なく、回転炉床炉だけにより還元鉄を製造することができる。また、回転炉床炉内で還元反応に伴い発生するＣＯガスは炉内で完全燃焼されるとともに、還元鉄を高温の状態で溶解炉に供給（熱間排出）して溶銑が製造されるため、エネルギー消費量やＣＯ２発生量を低減することができる等の利点が存在する。 According to this type of DR process, there is no need for a conventional sintering furnace or coke oven, and reduced iron can be produced only by a rotary hearth furnace. In addition, CO gas generated by the reduction reaction in the rotary hearth furnace is completely burned in the furnace, and hot metal is produced by supplying reduced iron to the melting furnace in a high temperature state (hot discharge). There is an advantage that energy consumption and CO 2 generation amount can be reduced.
　シャフト炉、回転炉床炉等の還元炉は基本的に連続運転される。これに対し、その下流側に設けられる溶解炉は、定期的にメンテナンスする必要があるため、その運転サイクルは上流側に設けられる還元炉とは異なっている。 The reduction furnaces such as shaft furnaces and rotary hearth furnaces are basically operated continuously. On the other hand, since the melting furnace provided in the downstream needs to be maintained regularly, the operation cycle is different from the reducing furnace provided in the upstream.
　溶解炉の稼働サイクルは還元炉のサイクルに比べて短く、また立ち上げ時には、還元炉と溶解炉の生産性が一致しない。 The operating cycle of the melting furnace is shorter than the cycle of the reducing furnace, and the productivity of the reducing furnace and the melting furnace does not match at startup.
　そこで、連続運転される還元炉と、比較的非連続運転される溶解炉との間のマッチングを図るために高温還元鉄貯蔵槽が設けられる。還元炉から排出された高温還元鉄は、一旦、上記高温還元鉄貯蔵槽に貯蔵され、溶解炉のニーズに応じて還元鉄を供給するようになっている。 Therefore, a high-temperature reduced iron storage tank is provided in order to achieve matching between a continuously operated reducing furnace and a relatively non-continuously operated melting furnace. The high-temperature reduced iron discharged from the reduction furnace is temporarily stored in the high-temperature reduced iron storage tank, and reduced iron is supplied according to the needs of the melting furnace.
　しかし、マッチングのために貯蔵槽（ホッパ）に長時間、還元鉄を滞留させると、還元鉄温度が下がり、溶解炉で使用する際に、著しく溶解炉の生産性が阻害される。また、設備構成が高温還元鉄の投入系統だけを有するものである場合には、温度降下した還元鉄を使用しない限り、還元炉の生産性もまた阻害されることになる。 However, if the reduced iron is retained in the storage tank (hopper) for a long time for matching, the reduced iron temperature is lowered, and the productivity of the melting furnace is significantly hindered when used in the melting furnace. Further, when the equipment configuration has only a high-temperature reduced iron charging system, the productivity of the reduction furnace is also hindered unless reduced iron whose temperature has dropped is used.
　以上のことから、高温還元鉄を単に溶解炉に投入する設備では、還元炉および溶解炉の生産性が低下するだけでなく、稼働率も低下する。また、立ち上げ時に低温ＤＲＩを使用したくても、切出能力がないと操業ができない。 From the above, in the facility in which high-temperature reduced iron is simply put into the melting furnace, not only the productivity of the reducing furnace and the melting furnace is lowered, but also the operation rate is lowered. Moreover, even if it is desired to use a low temperature DRI at the time of start-up, it cannot be operated without a cutting ability.
　本発明は、以上のような従来のＤＲプロセスにおける課題を考慮してなされたものである。本発明は、連続運転される回転炉床炉とバッチ運転される溶解炉とのマッチングを改善し、生産性を維持し、還元炉および溶解炉の稼働率を高めることができる溶鉄製造用原料投入装置および溶鉄製造用原料投入方法を提供するものである。 The present invention has been made in consideration of the problems in the conventional DR process as described above. The present invention improves the matching between a rotary hearth furnace that is operated continuously and a melting furnace that is operated in batch, maintains productivity, and can increase the operating rate of the reduction furnace and melting furnace, and can input raw materials for molten iron production An apparatus and a raw material charging method for producing molten iron are provided.
　本発明の溶鉄製造用原料投入装置は、直接還元製鉄プロセスで生産された高温還元鉄を溶解炉に熱間供給する高温用投入系統と、冷却された低温還元鉄および炭材を上記溶解炉に供給する低温用投入系統と、を有する溶鉄製造用原料投入装置であって、
　上記高温用投入系統は、熱間排出される還元鉄を貯溜する高温用貯溜容器と、この高温用貯溜容器内の高温還元鉄を所定量ずつ上記溶解炉に供給する定量切出装置と、を備え、
　上記低温用投入系統は、上記低温還元鉄を貯溜する第一ホッパと、この第一ホッパからの低温還元鉄の切出し量を調整するフィーダと、炭材を貯溜する第二ホッパと、この第二ホッパからの炭材切出し量を調整するフィーダと、を備えることを要旨とする。 The raw material charging apparatus for producing molten iron according to the present invention includes a high-temperature charging system for supplying hot high-temperature reduced iron produced by a direct reduction steelmaking process to a melting furnace, and cooled low-temperature reduced iron and carbonaceous material in the melting furnace. A raw material charging device for producing molten iron having a low temperature charging system to supply,
The high temperature charging system includes a high temperature storage container for storing reduced iron discharged hot, and a quantitative cutting device for supplying the high temperature reduced iron in the high temperature storage container to the melting furnace in a predetermined amount. Prepared,
The charging system for low temperature includes a first hopper for storing the low-temperature reduced iron, a feeder for adjusting a cutting amount of the low-temperature reduced iron from the first hopper, a second hopper for storing carbonaceous material, and the second hopper. And a feeder that adjusts the amount of carbon material cut out from the hopper.
　上記溶鉄製造用原料投入装置は、上記第一ホッパおよび上記第二ホッパから切り出される低温還元鉄および炭材を上記溶解炉に投入するための投入シュートを有し、上記溶解炉内の発生ガスの侵入を防止する遮断装置が上記投入シュートに介設されていることが好ましい。 The molten iron production raw material charging device has a charging chute for charging low-temperature reduced iron and carbonaceous material cut out from the first hopper and the second hopper into the melting furnace, and generates the generated gas in the melting furnace. It is preferable that a blocking device for preventing intrusion is interposed in the charging chute.
　上記低温用投入系統の切出し能力は、上記高温用投入系統の切出し能力の０～３０％を制御範囲とすることが好ましい。 The cutting ability of the low temperature charging system is preferably 0 to 30% of the cutting capacity of the high temperature charging system.
　本発明の溶鉄製造用原料投入方法は、直接還元製鉄プロセスで生産された高温還元鉄を溶解炉に熱間供給する高温用投入系統と、冷却された低温還元鉄および炭材を上記溶解炉に供給する低温用投入系統と、を有し、
　上記低温還元鉄および炭材は調整された投入速度で上記低温用投入系統から上記溶解炉に供給され、上記溶解炉内で上記低温還元鉄が溶解された後は、原料の投入が上記低温用投入系統から上記高温用投入系統に切り替えられることを要旨とする。 The raw material charging method for producing molten iron according to the present invention includes a high-temperature charging system for supplying hot high-temperature reduced iron produced by a direct reduction iron-making process to a melting furnace, and cooled low-temperature reduced iron and carbon material in the melting furnace. A low-temperature charging system to supply,
The low-temperature reduced iron and the carbonaceous material are supplied from the low-temperature charging system to the melting furnace at a controlled charging speed, and after the low-temperature reduced iron is dissolved in the melting furnace, the raw material is charged for the low-temperature. The gist is that the input system can be switched to the high temperature input system.
　また、上記溶解炉に還元鉄を投入する際に、低温還元鉄の投入速度を段階的に高め、上記高温還元鉄を速やかに定常の投入速度に到達させることが好ましい。 In addition, when reducing iron is charged into the melting furnace, it is preferable to increase the charging rate of low-temperature reduced iron stepwise so that the high-temperature reducing iron reaches a steady charging rate quickly.
　また、上記高温用投入系統により上記高温還元鉄を熱間供給する状態において、上記低温用投入系統から上記低温還元鉄を所定量投入し、溶湯温度が低下傾向にある場合には上記低温還元鉄の投入速度を下げ、溶湯温度が上昇傾向にある場合には上記低温還元鉄の投入速度を上げることにより、上記高温還元鉄の投入速度を一定にしたまま、溶湯温度を一定に維持することができる。 In the state where the high temperature reduced iron is supplied hot by the high temperature charging system, when a predetermined amount of the low temperature reduced iron is charged from the low temperature charging system and the molten metal temperature tends to decrease, the low temperature reduced iron is used. When the molten metal temperature tends to rise, the molten metal temperature can be kept constant by increasing the low-temperature reduced iron charging speed while keeping the high-temperature reduced iron charging speed constant. it can.
　また、本発明の溶鉄製造用原料投入方法は、直接還元製鉄プロセスで生産された高温還元鉄を溶解炉に熱間供給する高温用投入系統と、冷却された低温還元鉄および炭材を上記溶解炉に供給する低温用投入系統と、を有し、
　上記高温用投入系統により上記高温還元鉄を熱間供給する状態において、上記低温用投入系統から上記低温還元鉄を所定量投入し、溶湯温度が低下傾向にある場合には上記低温還元鉄の投入速度を下げ、溶湯温度が上昇傾向にある場合には上記低温還元鉄の投入速度を上げて溶湯温度を一定に維持することを要旨とする。 In addition, the raw material charging method for producing molten iron according to the present invention includes a high temperature charging system for supplying hot high-temperature reduced iron produced by a direct reduction iron-making process to a melting furnace, and melting the cooled low-temperature reduced iron and carbonaceous material as described above. A low-temperature charging system for supplying to the furnace,
In a state where the high temperature reduced iron is supplied hot by the high temperature charging system, a predetermined amount of the low temperature reduced iron is charged from the low temperature charging system, and when the molten metal temperature tends to decrease, the low temperature reduced iron is charged. The gist is to keep the melt temperature constant by lowering the speed and increasing the charging speed of the low-temperature reduced iron when the melt temperature tends to rise.
　本発明は、連続運転される還元炉と非連続的に運転される溶解炉とのマッチングが改善でき、所定の生産性を維持して各炉の稼働率を高めることができるという長所を有する。 The present invention has the advantage that the matching between the reducing furnace operated continuously and the melting furnace operated discontinuously can be improved, and the operating rate of each furnace can be increased while maintaining a predetermined productivity.
本発明に係る原料投入装置の構成を示す説明図である。It is explanatory drawing which shows the structure of the raw material injection device which concerns on this invention. 本発明に係る原料投入装置の制御動作を示したグラフである。It is the graph which showed the control operation of the raw material injection device concerning the present invention. 本発明に係る原料投入装置の制御動作を示したグラフである。It is the graph which showed the control operation of the raw material injection device concerning the present invention.
符号の説明Explanation of symbols
１　直接還元製鉄設備 
２　回転炉床炉
２ａ　回転炉床
２ｂ　炉体 
２ｃ　加熱バーナー
３　高温ＤＲＩ搬送容器
４　原料投入装置 
５　中間ビン（高温用貯溜容器）
５ａ　上部接続部
５ｂ　上側スライドゲート
５ｃ　下側スライドゲート
６　水冷式スクリューフィーダ（定量切出装置）
７　フィードビン
７ａ　上側スライドゲート
７ｂ　下側スライドゲート
８　投入部
９　溶解炉
１０　高温用投入系統
１１　低温用投入系統
１２　低温ＤＲＩホッパ（第一ホッパ）
１３　振動フィーダ（フィーダ）
１４　石炭ホッパ（第二ホッパ）
１５　振動フィーダ（フィーダ）
１６　コンベヤ
１６ａ　ホッパ
１７　シュート（投入シュート）
１７ａ　ロータリーバルブ（遮断装置）
１８　酸素吹込みランス 1 Direct reduction steelmaking equipment
2 Rotary hearth furnace 2a Rotary hearth furnace 2b Furnace body
2c Heating burner 3 High temperature DRI transfer container 4 Raw material charging device
5 Intermediate bottle (high temperature storage container)
5a Upper connection part 5b Upper slide gate 5c Lower slide gate 6 Water-cooled screw feeder (quantitative cutting device)
7 Feed Bin 7a Upper Slide Gate 7b Lower Slide Gate 8 Input Port 9 Melting Furnace 10 High Temperature Input System 11 Low Temperature Input System 12 Low Temperature DRI Hopper (First Hopper)
13 Vibration feeder (feeder)
14 Coal hopper (second hopper)
15 Vibration feeder (feeder)
16 Conveyor 16a Hopper 17 Chute (input chute)
17a Rotary valve (shut-off device)
18 Oxygen blowing lance
　以下、図面に示した実施の形態に基づいて本発明を詳細に説明する。 Hereinafter, the present invention will be described in detail based on the embodiments shown in the drawings.
　１．直接還元製鉄設備の構成 
　図１は、本発明に係る溶鉄製造用原料投入装置（以下、原料投入装置と呼ぶ）を直接還元製鉄設備に適用した場合の構成を示す。 1. Structure of direct reduction steelmaking equipment
FIG. 1 shows a configuration in a case where a raw material charging apparatus for producing molten iron according to the present invention (hereinafter referred to as a raw material charging apparatus) is directly applied to a reduction iron making facility.
　図１において、直接還元製鉄設備１は、回転炉床式加熱還元炉（以下、回転炉床炉と呼ぶ）２を有し、この回転炉床炉２の回転炉床２ａは、反時計方向（矢印Ａ方向）に回転するようになっている。 In FIG. 1, a direct reduction iron making facility 1 has a rotary hearth type heating reduction furnace (hereinafter referred to as a rotary hearth furnace) 2, and the rotary hearth 2 a of the rotary hearth furnace 2 is counterclockwise ( It rotates in the direction of arrow A).
　回転炉床炉２の回転速度は、加熱還元炉の大きさや操業条件によって異なるが、通常は６分から１６分程度で１周するようになっている。 The rotational speed of the rotary hearth furnace 2 varies depending on the size and operating conditions of the heating and reducing furnace, but usually makes one turn in about 6 to 16 minutes.
　また、回転炉床炉２における炉体２ｂの壁面には加熱バーナー２ｃが複数個設けられており、これらの加熱バーナー２ｃによる燃焼熱あるいはその輻射熱によって炉床部に熱が供給される。 Further, a plurality of heating burners 2c are provided on the wall surface of the furnace body 2b in the rotary hearth furnace 2, and heat is supplied to the hearth by combustion heat or radiant heat generated by these heating burners 2c.
　耐火材で構成された回転炉床２ａ上に装入された原料混合物Ｍは、回転炉床２ａ上で回転炉床炉２内を周方向へ移動する間、加熱バーナー２ｃからの燃焼熱や輻射熱によって加熱される。そして回転炉床炉２内の加熱帯を通過する間に、原料混合物Ｍ内の酸化鉄は、還元され、副生する溶融スラグと分離すると共に残余の炭素質還元剤による浸炭を受けて溶融しながら、粒状に凝集して粒状還元鉄Ｎとなる。 While the raw material mixture M charged on the rotary hearth 2a made of refractory material moves in the rotary hearth furnace 2 in the circumferential direction on the rotary hearth 2a, the combustion heat and radiant heat from the heating burner 2c. Heated by. While passing through the heating zone in the rotary hearth furnace 2, the iron oxide in the raw material mixture M is reduced and separated from the by-product molten slag and melted by receiving carburization with the remaining carbonaceous reducing agent. However, it aggregates in a granular form and becomes granular reduced iron N.
　さらに、回転炉床炉２の回転下流側ゾーンから高温のまま排出された粒状還元鉄Ｎは、高温ＤＲＩ搬送容器３に収容され、原料投入装置４に移動される。 Further, the granular reduced iron N discharged from the rotary downstream zone of the rotary hearth furnace 2 at a high temperature is accommodated in the high temperature DRI transfer container 3 and moved to the raw material charging device 4.
　２．原料投入装置の構成
　原料投入装置４は、直接還元製鉄プロセスで生産された高温還元鉄を後述する溶解炉に熱間供給する高温用投入系統１０と、冷却された低温還元鉄および炭材を溶解炉に供給する低温用投入系統１１と、から構成されている。 2. Composition of raw material charging device The raw material charging device 4 melts the cooled low-temperature reduced iron and carbonaceous material, and the high-temperature charged system 10 for supplying hot high-temperature reduced iron produced in the direct reduction steelmaking process to a melting furnace described later. And a low temperature charging system 11 to be supplied to the furnace.
　２－１．高温用投入系統
　原料投入装置４の高温用投入系統１０に移動された高温ＤＲＩ搬送容器３は、中間ビン（高温用貯溜容器）５の上部接続部５ａに接続される。 2-1. High temperature charging system The high temperature DRI transport container 3 moved to the high temperature charging system 10 of the raw material charging device 4 is connected to the upper connection portion 5 a of the intermediate bin (high temperature storage container) 5.
　中間ビン５は、上側スライドゲート５ｂと、下側スライドゲート５ｃと、を備えている。また、中間ビン５の下方には上記高温用投入装置としての水冷式スクリューフィーダ（定量切出装置）６が設けられており、この水冷式スクリューフィーダ６の下方にさらにロードセル付きのフィードビン７が設けられている。 The intermediate bin 5 includes an upper slide gate 5b and a lower slide gate 5c. A water-cooled screw feeder (quantitative cutting device) 6 as a high-temperature charging device is provided below the intermediate bottle 5, and a feed bin 7 with a load cell is further provided below the water-cooled screw feeder 6. Is provided.
　上記水冷式スクリューフィーダ６の切出し能力（定格）は５ｔ／ｈである。これに対し、低温用投入系統１１における振動フィーダの切出し能力（定格）は１．５ｔ／ｈであり、高温用投入系統１０の切出し能力の３０％である。 The cutting ability (rated) of the water-cooled screw feeder 6 is 5 t / h. In contrast, the cutting ability (rated) of the vibration feeder in the low temperature charging system 11 is 1.5 t / h, which is 30% of the cutting capacity of the high temperature charging system 10.
　通常、切出し能力の下限以下では制御性が悪く、使用することができない。本実施形態の水冷式スクリューフィーダ６も例外ではなく、制御可能な最低投入速度は約１，０００ｋｇ／h（定格の約２０％）であった。 Normally, controllability is poor below the lower limit of the cutting ability and cannot be used. The water-cooled screw feeder 6 of this embodiment is no exception, and the minimum controllable charging speed was about 1,000 kg / h (about 20% of the rating).
　これに対し、低温用投入系統１１における振動フィーダの切出し能力（定格）は１．５ｔ／ｈであるため、高温用投入系統１０における切出し能力の少なくとも０～３０％までの制御範囲を、低温用投入系統１１でカバーすることが可能になる。 On the other hand, since the cutting capacity (rated) of the vibration feeder in the low temperature charging system 11 is 1.5 t / h, a control range of at least 0 to 30% of the cutting capacity in the high temperature charging system 10 is set for low temperature. It is possible to cover with the input system 11.
　詳しくは、高温用投入系統１０は、本実施形態では８００℃の高温ＤＲＩを処理することをベースに設計されている。また、低温（常温）ＤＲＩを溶解するために必要なエネルギーは、上記高温用投入系統１０の約１．５倍必要である。したがって、高温用投入系統１０において制御が困難な定格の約２０％について、低温用投入系統１１で制御可能にするためには、２０％×１．５＝３０％の切出し能力（最大）が必要になる。従って、低温用投入系統１１の切出し能力は、高温用投入系統１０の切出し能力の０～３０％をカバーできるものが望ましい。 Specifically, the high temperature charging system 10 is designed based on processing a high temperature DRI of 800 ° C. in this embodiment. Further, the energy required for dissolving the low temperature (normal temperature) DRI is required to be about 1.5 times that of the high temperature charging system 10. Therefore, about 20% of the rating that is difficult to control in the high temperature charging system 10, a cutting capacity (maximum) of 20% × 1.5 = 30% is required in order to enable control in the low temperature charging system 11. become. Therefore, it is desirable that the cutting capacity of the low temperature charging system 11 can cover 0 to 30% of the cutting capacity of the high temperature charging system 10.
　回転炉床炉２と溶解炉（後述する）との連続プロセス（ホットリンクプロセス）は必ずしもマッチングしないため、常に余剰の還元鉄を製造する必要がある。また、溶解炉の立ち上げ時や回転炉床炉休止中の溶解炉の稼働は生産性が低いため、低温用還元鉄を投入する等の対応を取る必要性がある。 Since the continuous process (hot link process) of the rotary hearth furnace 2 and the melting furnace (described later) does not always match, it is necessary to always produce surplus reduced iron. Further, since the productivity of the melting furnace is low when the melting furnace is started up or when the rotary hearth furnace is stopped, it is necessary to take measures such as introducing reduced iron for low temperature.
　そのため、単に高温用投入系統１０の制御域をカバーするだけでなく、上述した場合においても高温用投入系統１０の代替ができるように、振動フィーダの切出し能力は３０％に設定される。３０％を上回る切出し能力に設定することも可能ではあるが、そうすると原料投入装置４の規模が大型化してしまい、プラントコストが高くなるだけでなく制御も複雑になる。 Therefore, in addition to simply covering the control range of the high temperature charging system 10, the cutting ability of the vibration feeder is set to 30% so that the high temperature charging system 10 can be substituted even in the case described above. Although it is possible to set the cutting capacity exceeding 30%, the scale of the raw material charging device 4 is increased, which not only increases the plant cost but also complicates the control.
　なお、連続プロセスのマッチング状況に応じ、切出し能力が３０％以下の振動フィーダを複数設けることもできる。 It should be noted that a plurality of vibration feeders having a cutting ability of 30% or less can be provided according to the matching status of the continuous process.
　また、フィードビン７には、上側スライドゲート７ａと下側スライドゲート７ｂとが備えられており、フィードビン７の下部は、投入部８を介して溶解炉９と接続されている。 Further, the feed bin 7 is provided with an upper slide gate 7 a and a lower slide gate 7 b, and the lower portion of the feed bin 7 is connected to the melting furnace 9 through the charging unit 8.
　上記スライドゲート７ａ、７ｂを設ける理由は下記の通りである。フィードビン７より上流側の投入系統はシール性が低いため、溶解炉運転中に発生した排ガスが、フィードビン７の上流側に流入し、外気と接触することにより発火などの危険性がある。フィードビン７の上側および下側スライドゲート７ａ、７ｂは、排ガスがフィードビン７の上流側へ流入することを防ぐ効果がある。 The reason why the slide gates 7a and 7b are provided is as follows. Since the input system upstream of the feed bin 7 has low sealing performance, exhaust gas generated during the operation of the melting furnace flows into the upstream side of the feed bin 7 and comes into contact with the outside air, which may cause ignition. The upper and lower slide gates 7 a and 7 b of the feed bin 7 have an effect of preventing exhaust gas from flowing into the upstream side of the feed bin 7.
　また、上記スライドゲート５ｂ，５ｃおよびスライドゲート７ａ，７ｂは、溶解炉９内からの発生ガスが高温用投入系統１０に侵入することを防止するために設けられる。 The slide gates 5b and 5c and the slide gates 7a and 7b are provided in order to prevent the gas generated from the melting furnace 9 from entering the high temperature charging system 10.
　２－２．低温用投入系統
　一方、投入部８には高温用投入系統１０とは別に低温用投入系統１１が設けられている。 2-2. On the other hand, the charging unit 8 is provided with a low temperature charging system 11 in addition to the high temperature charging system 10.
　この低温用投入系統１１は、低温ＤＲＩホッパ（第１ホッパ）１２と、この低温ＤＲＩホッパ１２から低温ＤＲＩの切出しを行なう低温用投入装置としての振動フィーダ（フィーダ）１３と、石炭ホッパ（第２ホッパ）１４と、この石炭ホッパ１４から炭材の切出しを行なう同じく低温用投入装置としての振動フィーダ（フィーダ）１５と、これらのホッパから供給される原料を先上がりに搬送するためのコンベヤ１６と、このコンベヤ１６の先端部に設けられたホッパ１６ａと上記投入部８とを連通させるシュート（投入シュート）１７と、このシュート１７に設けられたロータリーバルブ（遮断装置）１７ａと、から主として構成されている。 The low temperature charging system 11 includes a low temperature DRI hopper (first hopper) 12, a vibration feeder (feeder) 13 as a low temperature charging device for cutting out the low temperature DRI from the low temperature DRI hopper 12, and a coal hopper (second hopper). Hopper) 14, a vibration feeder (feeder) 15 as a low temperature charging device for cutting out carbonaceous material from the coal hopper 14, and a conveyor 16 for conveying the raw material supplied from these hoppers forward The hopper 16a provided at the front end portion of the conveyor 16 and the chute (feed chute) 17 communicating with the throwing portion 8 and a rotary valve (blocking device) 17a provided on the chute 17 are mainly configured. ing.
　なお、遮断装置は、上記ロータリーバルブに限らず、二重ダンパ式開閉弁等で構成することもできる。  Note that the shut-off device is not limited to the rotary valve, and can be constituted by a double damper on-off valve or the like.
　上記ロータリーバルブ１７ａは、溶解炉９内からの発生ガスが低温用投入系統１１に侵入することを防止している。 The rotary valve 17a prevents gas generated from the melting furnace 9 from entering the low temperature charging system 11.
　なお、連続切出し装置としては上記振動フィーダを用いることが好ましいが、これに限らず、スクリューフィーダ、テーブルフィーダ等、他方式のフィーダを用いることもできる。 In addition, although it is preferable to use the said vibration feeder as a continuous cutting device, it is not restricted to this, Feeders of other systems, such as a screw feeder and a table feeder, can also be used.
　上記溶解炉９には、溶解炉９の湯面上のスラグ層に向けて高純度の酸素を吹込むための酸素吹込みランス１８が設けられている。この酸素吹込みランス１８から溶解炉９に投入される酸素源と炭材とを反応（燃焼）させることにより、還元鉄中に残存する未還元の酸化鉄が還元されるとともに還元鉄が加熱・溶解され、溶銑を製造するようになっている。 The melting furnace 9 is provided with an oxygen blowing lance 18 for blowing high-purity oxygen toward the slag layer on the molten metal surface of the melting furnace 9. By reacting (combusting) the oxygen source and the carbonaceous material charged into the melting furnace 9 from the oxygen blowing lance 18, unreduced iron oxide remaining in the reduced iron is reduced and the reduced iron is heated and heated. It is melted to produce hot metal.
　３．原料投入装置の投入動作 
　次に、上記構成を有する原料投入装置４の投入動作について、図２および図３を参照しながら説明する。 3. Input operation of raw material input device
Next, the charging operation of the raw material charging apparatus 4 having the above configuration will be described with reference to FIGS.
　３－１．立ち上げ時
　図２は溶解炉９の運転初期から定常期に至るまでの制御動作をグラフで示したものであり、回転炉床炉２は連続運転されていることを前提とする。  3-1. FIG. 2 is a graph showing the control operation from the initial operation to the stationary phase of the melting furnace 9, and it is assumed that the rotary hearth furnace 2 is continuously operated.
　図２において、横軸は吹錬開始からの経過時間（分）を示す。左側縦軸は送酸速度（Ｎｍ３／h）及び炭材・ＤＲＩ投入速度（ｋｇ／ｈ）を示す。右側縦軸は溶湯温度（℃）を示す。 In FIG. 2, the horizontal axis indicates the elapsed time (minutes) from the start of blowing. The vertical axis on the left indicates the acid feed rate (Nm 3 / h) and the carbonaceous material / DRI feed rate (kg / h). The right vertical axis indicates the molten metal temperature (° C.).
　図２において送酸速度Ｏは一定であり、炭材投入速度Ｃは１０分経過した時点から一定である。 In FIG. 2, the acid feed rate O is constant, and the carbonaceous material feed rate C is constant after 10 minutes.
　送酸設備の規模が大きくなることを避けることが好ましいため、できれば送酸速度を一定にして運転することが望まれる。しかしながら、還元プロセスの稼働率を高めるために回転炉床炉２から排出される還元鉄量のすべてをそのまま溶解炉９に供給すると、溶解炉９の溶湯温度を制御する手段がなくなるため、還元プロセスが成り立たなくなってしまう。 Since it is preferable to avoid an increase in the scale of the acid delivery facility, it is desirable to operate with a constant acid delivery rate if possible. However, if all the amount of reduced iron discharged from the rotary hearth furnace 2 is supplied as it is to the melting furnace 9 in order to increase the operating rate of the reduction process, there is no means for controlling the molten metal temperature of the melting furnace 9, so that the reduction process Will not hold true.
　そこで、従来は、溶解炉９の溶湯温度が低い場合には還元鉄Ｎの供給量を減らし、溶湯温度が高い場合には還元鉄Ｎの供給量を増やすという処理が行なわれていた。 Therefore, conventionally, when the molten metal temperature of the melting furnace 9 is low, the supply amount of the reduced iron N is reduced, and when the molten metal temperature is high, the supply amount of the reduced iron N is increased.
　これに対し、本発明の原料投入装置４は、高温用投入系統１０とは別に、低温用投入系統１１を備える。この低温用投入系統１１から投入される低温ＤＲＩおよび炭材の量を制御することにより、回転炉床炉２から排出される還元鉄Ｎ量はそのまま溶解炉９に供給できる。なお、炭材は、ＦｅＯを高濃度で含有するスラグを還元するために投入される。 On the other hand, the raw material charging apparatus 4 of the present invention includes a low temperature charging system 11 separately from the high temperature charging system 10. The amount of reduced iron N discharged from the rotary hearth furnace 2 can be supplied to the melting furnace 9 as it is by controlling the amount of the low temperature DRI and the carbonaceous material charged from the low temperature charging system 11. The carbonaceous material is added to reduce slag containing FeO at a high concentration.
　そのための制御方法として、低温ＤＲＩ投入速度Ｌおよび炭材投入速度Ｃは、溶解炉９の運転立ち上げからそれぞれ段階的に高められる。 As a control method therefor, the low temperature DRI charging speed L and the carbonaceous material charging speed C are increased step by step from the start-up of the melting furnace 9.
　図１に示したロータリーバルブ１７ａを動作させた状態で、振動フィーダ１３，１５の振動数を高めることにより低温ＤＲＩ投入速度Ｌと炭材投入速度Ｃが上昇されると、溶解炉９内の溶湯温度Ｔが上昇する。そして溶湯温度Ｔが１４５０℃を超えた時点で、振動フィーダ１３，１５をオフし、低温ＤＲＩの投入を停止する。ただし、炭材投入速度Ｃは一定のままである。 When the rotary valve 17a shown in FIG. 1 is operated and the low frequency DRI charging speed L and the carbonaceous material charging speed C are increased by increasing the frequency of the vibration feeders 13 and 15, the molten metal in the melting furnace 9 The temperature T rises. When the molten metal temperature T exceeds 1450 ° C., the vibration feeders 13 and 15 are turned off, and the introduction of the low temperature DRI is stopped. However, the carbonaceous material charging speed C remains constant.
　図２中、矢印Ｂは、低温ＤＲＩ投入から高温ＤＲＩ投入への切り替えのタイミングを示している。 In FIG. 2, an arrow B indicates the timing of switching from low temperature DRI input to high temperature DRI input.
　このように、溶解炉９の溶湯温度Ｔが所定の温度に到達した時点で、高温ＤＲＩの投入に切り替えれば、ロスを発生することなく回転炉床炉２と溶解炉９の運転とをマッチングさせることが可能になる。そして、高温ＤＲＩへの切り替え後、高温ＤＲＩ投入速度Ｈを段階的に増加させることにより、溶解炉９内の溶湯温度Ｔの推移は、切り替えのタイミングＢ点を境にして上昇から安定に移行することになる。 In this way, when the molten metal temperature T of the melting furnace 9 reaches a predetermined temperature, switching to the introduction of the high-temperature DRI matches the operation of the rotary hearth furnace 2 and the melting furnace 9 without generating a loss. It becomes possible. Then, after switching to the high temperature DRI, by gradually increasing the high temperature DRI charging speed H, the transition of the molten metal temperature T in the melting furnace 9 shifts stably from the rise at the switching timing B point. It will be.
　３－２．定常運転時
　図３は、定常運転を行なうための投入動作をグラフで示したものである。 3-2. At the time of steady operation FIG. 3 is a graph showing the charging operation for performing steady operation.
　回転炉床炉２から排出される還元鉄量はすべてそのまま溶解炉９に供給されるので、高温ＤＲＩ投入速度Ｈは一定である。また、炭材投入速度Ｃおよび送酸速度Ｏも一定である。 Since all of the reduced iron discharged from the rotary hearth furnace 2 is supplied to the melting furnace 9 as it is, the high temperature DRI charging speed H is constant. Further, the carbon material charging speed C and the acid feeding speed O are also constant.
　溶湯温度Ｔが低下傾向にあるときは、低温ＤＲＩ投入速度Ｌを下げる（グラフ中、立下り部Ｌ１参照）ことにより、溶湯温度Ｔの低下が抑えられる。 When the melt temperature T tends to decrease lowers the cold DRI addition rate L by (in the graph, standing reference downlink portion L 1) that reduction of the melt temperature T is suppressed.
　一方、溶湯温度Ｔが上昇傾向にあるときは、低温ＤＲＩ投入速度Ｌを上げる（グラフ中、立上がり部Ｌ２参照）ことにより、溶湯温度Ｔの上昇が抑えられる。 On the other hand, when the melt temperature T tends to increase the cold DRI input rate increases the L by (in the graph, the rising portion L 2 reference) that the increase in the melt temperature T is suppressed.
　低温ＤＲＩ投入速度Ｌを上げることによって溶湯温度Ｔの上昇が抑制された後、溶湯温度Ｔが徐々に低下する傾向を示すときは、低温ＤＲＩ投入速度Ｌを若干下げる（グラフ中、立下り部Ｌ３参照）。 After the rise of the molten metal temperature T is suppressed by increasing the low temperature DRI charging speed L, when the molten metal temperature T shows a tendency to gradually decrease, the low temperature DRI charging speed L is slightly decreased (in the graph, the falling portion L 3 ).
　このように、溶湯温度Ｔの傾向を見ながら低温ＤＲＩの投入速度を調節することによって、溶湯温度Ｔの変動を抑制しながら連続運転を行なうことができる。 Thus, by adjusting the charging speed of the low temperature DRI while observing the trend of the molten metal temperature T, continuous operation can be performed while suppressing fluctuations in the molten metal temperature T.
　上記実施形態では、本発明の原料投入装置は、回転炉床炉と溶解炉との間に介設した場合を例に説明した。しかしながら、本発明の原料投入装置は、回転炉床炉に限らず、直接還元製鉄プロセスを行なう任意の炉と溶解炉との間に介設することができる。 In the above embodiment, the case where the raw material charging device of the present invention is interposed between the rotary hearth furnace and the melting furnace has been described as an example. However, the raw material charging apparatus of the present invention is not limited to a rotary hearth furnace, and can be interposed between any furnace that performs a direct reduction iron making process and a melting furnace.
　以上のとおり、本発明を詳細に、また特定の実施態様を参照して説明したが、本発明の精神と範囲を逸脱することなく様々な変更や修正を加えることができることは当業者にとって明らかである。本出願は２００８年３月２８日出願の日本特許出願（特願２００８－０８７６５４）に基づくものであり、その内容はここに参照として取り込まれる。 Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. is there. This application is based on a Japanese patent application filed on Mar. 28, 2008 (Japanese Patent Application No. 2008-087654), the contents of which are incorporated herein by reference.

Claims (7)

  1. 　直接還元製鉄プロセスで生産された高温還元鉄を溶解炉に熱間供給する高温用投入系統と、冷却された低温還元鉄および炭材を上記溶解炉に供給する低温用投入系統と、を有する溶鉄製造用原料投入装置であって、
    　上記高温用投入系統は、熱間排出される還元鉄を貯溜する高温用貯溜容器と、この高温用貯溜容器内の高温還元鉄を所定量ずつ上記溶解炉に供給する定量切出装置と、を備え、
    　上記低温用投入系統は、上記低温還元鉄を貯溜する第一ホッパと、この第一ホッパからの低温還元鉄の切出し量を調整するフィーダと、炭材を貯溜する第二ホッパと、この第二ホッパからの炭材の切出し量を調整するフィーダと、を備えることを特徴とする溶鉄製造用原料投入装置。     Molten iron having a high temperature charging system that supplies hot high-temperature reduced iron produced by the direct reduction iron making process to the melting furnace and a low-temperature charging system that supplies cooled low-temperature reduced iron and charcoal to the melting furnace A raw material charging device for manufacturing,
    The high temperature charging system includes a high temperature storage container for storing reduced iron discharged hot, and a quantitative cutting device for supplying the high temperature reduced iron in the high temperature storage container to the melting furnace in a predetermined amount. Prepared,
    The charging system for low temperature includes a first hopper for storing the low-temperature reduced iron, a feeder for adjusting a cutting amount of the low-temperature reduced iron from the first hopper, a second hopper for storing carbonaceous material, and the second hopper. And a feeder for adjusting the amount of carbon material cut out from the hopper.
  2. 　上記第一ホッパおよび上記第二ホッパから切り出される低温還元鉄および炭材を上記溶解炉に投入するための投入シュートを有し、上記溶解炉内の発生ガスの侵入を防止する遮断装置が上記投入シュートに介設されている請求項１記載の溶鉄製造用原料投入装置。 A shut-off device that has a charging chute for charging low-temperature reduced iron and carbon material cut out from the first hopper and the second hopper into the melting furnace and prevents the intrusion of the generated gas in the melting furnace is the charging The raw material charging apparatus for producing molten iron according to claim 1, which is interposed in the chute.
  3. 　上記低温用投入系統の切出し能力は、上記高温用投入系統の切出し能力の０～３０％を制御範囲とする請求項１または２記載の溶鉄製造用原料投入装置。 3. The raw material charging device for manufacturing molten iron according to claim 1 or 2, wherein the cutting capacity of the low temperature charging system is controlled within 0 to 30% of the cutting capacity of the high temperature charging system.
  4. 　直接還元製鉄プロセスで生産された高温還元鉄を溶解炉に熱間供給する高温用投入系統と、冷却された低温還元鉄および炭材を上記溶解炉に供給する低温用投入系統と、を有し、
    　上記低温還元鉄および炭材は調整された投入速度で上記低温用投入系統から上記溶解炉に供給され、上記溶解炉内で上記低温還元鉄が溶解された後は、原料の投入が上記低温用投入系統から上記高温用投入系統に切り替えられることを特徴とする溶鉄製造用原料投入方法。     A high temperature charging system that supplies hot reduced iron produced by the direct reduction iron making process to the melting furnace and a low temperature charging system that supplies cooled low-temperature reduced iron and charcoal to the melting furnace. ,
    The low-temperature reduced iron and the carbonaceous material are supplied from the low-temperature charging system to the melting furnace at a controlled charging speed, and after the low-temperature reduced iron is dissolved in the melting furnace, the raw material is charged for the low-temperature. A method for charging a raw material for producing molten iron, wherein the charging system is switched from the charging system to the high temperature charging system.
  5. 　上記低温還元鉄の投入速度を段階的に高め、上記高温還元鉄を速やかに定常の投入速度に到達させる請求項４記載の溶鉄製造用原料投入方法。 The method for charging raw material for producing molten iron according to claim 4, wherein the charging rate of the low-temperature reduced iron is increased stepwise to allow the high-temperature reduced iron to quickly reach a steady charging rate.
  6. 　上記高温用投入系統により上記高温還元鉄を熱間供給する状態において、上記低温用投入系統から上記低温還元鉄を所定量投入し、溶湯温度が低下傾向にある場合には上記低温還元鉄の投入速度を下げ、溶湯温度が上昇傾向にある場合には上記低温還元鉄の投入速度を上げることにより、溶湯温度が一定に維持されると共に上記高温還元鉄の投入速度が一定に維持される請求項４または５記載の溶鉄製造用原料投入方法。 In a state where the high temperature reduced iron is supplied hot by the high temperature charging system, a predetermined amount of the low temperature reduced iron is charged from the low temperature charging system, and when the molten metal temperature tends to decrease, the low temperature reduced iron is charged. The molten metal temperature is maintained constant and the charging speed of the high-temperature reduced iron is maintained constant by decreasing the speed and increasing the charging speed of the low-temperature reduced iron when the molten metal temperature is increasing. The raw material charging method for producing molten iron according to 4 or 5.
  7. 　直接還元製鉄プロセスで生産された高温還元鉄を溶解炉に熱間供給する高温用投入系統と、冷却された低温還元鉄および炭材を上記溶解炉に供給する低温用投入系統と、を有し、
    　上記高温用投入系統により上記高温還元鉄を熱間供給する状態において、上記低温用投入系統から上記低温還元鉄を所定量投入し、溶湯温度が低下傾向にある場合には上記低温還元鉄の投入速度を下げ、溶湯温度が上昇傾向にある場合には上記低温還元鉄の投入速度を上げることにより、溶湯温度が一定に維持されることを特徴とする溶鉄製造用原料投入方法。     A high temperature charging system that supplies hot reduced iron produced by the direct reduction iron making process to the melting furnace and a low temperature charging system that supplies cooled low-temperature reduced iron and charcoal to the melting furnace. ,
    In a state where the high temperature reduced iron is supplied hot by the high temperature charging system, a predetermined amount of the low temperature reduced iron is charged from the low temperature charging system, and when the molten metal temperature tends to decrease, the low temperature reduced iron is charged. A method for charging a raw material for producing molten iron, wherein the molten metal temperature is maintained constant by decreasing the speed and increasing the charging speed of the low-temperature reduced iron when the molten metal temperature tends to increase.
PCT/JP2009/056381 2008-03-28 2009-03-27 Raw material introduction apparatus for molten iron making and method for introducing raw material for molten iron making WO2009119843A1 (en)

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JPH11217617A (en) * 1998-01-29 1999-08-10 Nkk Corp Method for supplying raw material into metallurgical furnace and apparatus therefor
JP2000054014A (en) * 1998-07-31 2000-02-22 Nkk Corp Device for charging ore in smelting reduction equipment
JP2002097507A (en) * 2000-09-19 2002-04-02 Mitsubishi Heavy Ind Ltd Molten pig iron production process and equipment for the same
WO2006046606A1 (en) * 2004-10-29 2006-05-04 Kabushiki Kaisha Kobe Seiko Sho Process for producing molten iron and apparatus therefor

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JPH11217617A (en) * 1998-01-29 1999-08-10 Nkk Corp Method for supplying raw material into metallurgical furnace and apparatus therefor
JP2000054014A (en) * 1998-07-31 2000-02-22 Nkk Corp Device for charging ore in smelting reduction equipment
JP2002097507A (en) * 2000-09-19 2002-04-02 Mitsubishi Heavy Ind Ltd Molten pig iron production process and equipment for the same
WO2006046606A1 (en) * 2004-10-29 2006-05-04 Kabushiki Kaisha Kobe Seiko Sho Process for producing molten iron and apparatus therefor

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